Previous work had shown that, in some Staphylococcus aureus strains, low concentrations of the virulent phage vB_SauM_phiIPLA-RODI (phiIPLA-RODI) promoted the formation of DNA-rich biofilms, whose cells exhibited significant transcriptional differences compared to an uninfected control. This study aimed to dissect the sequence of events leading to these changes. Analysis of phage propagation throughout biofilm development revealed that the number of phage particles increased steadily up to a certain point and then declined. This partial phage inactivation seemed to be a consequence of medium acidification due to glucose fermentation by the bacterium. Computer simulation of phage–host dynamics during biofilm development showed how even small differences in pH evolution can affect the outcome of phage infection. An acidic pH, together with successful phage propagation, was also necessary to observe the phage-associated changes in biofilm architecture and in the transcriptional profile of the bacterial population. Altogether, this study shows how the dynamics between phage and host can be tightly coordinated through an environmental cue, even in the context of a complex biofilm population.

以前的工作表明，在一些金黄色葡萄球菌中在菌株中，低浓度的毒性噬菌体 vB_SauM_phiIPLA-RODI (phiIPLA-RODI) 促进了富含 DNA 的生物膜的形成，与未感染的对照相比，其细胞表现出显着的转录差异。本研究旨在剖析导致这些变化的事件顺序。对整个生物膜发育过程中噬菌体繁殖的分析表明，噬菌体颗粒的数量稳定增加到某个点，然后下降。这种部分噬菌体失活似乎是由于细菌葡萄糖发酵导致的培养基酸化的结果。生物膜发育过程中噬菌体-宿主动力学的计算机模拟表明，即使 pH 值演变的微小差异也会影响噬菌体感染的结果。酸性 pH 值以及成功的噬菌体繁殖，还需要观察生物膜结构和细菌种群转录谱中与噬菌体相关的变化。总而言之，这项研究表明，即使在复杂的生物膜种群背景下，噬菌体和宿主之间的动态也可以通过环境线索紧密协调。